Former for filaments for incandescent electric lamps.



No. 694,220. Patented Feb. 25, I902.

G. C. WEBSTER. FORMER FOR FILAMENTS FOR INCANDESGENT ELECTRIC LAMPS.

(Application filed Dec. so, 1901.)

(No Model.)

//v VENTOR Glam. Cit aisle 1 A TTORNEYS UNITED STATES PATENT OFFICE.

GLENN CANNON WEBSTER, OF WARREN, OHIO.

FORMER FOR FILAMENTS FO-R INCA'NDESCENT ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 694,220, dated February25, 1902. Application filed December 30, 1901. Serial No. 87,728. (Nomodel.)

To (0 whom it may concern:

Be it known that I, GLENN CANNON WEB- STER, a citizen of the UnitedStates, residing at Warren, in the county of Trumbull and State of Ohio,have made certain new and useful Improvements in Formers for Filamentsfor Incandescent Electric Lamps, of which the following is aspecification.

I have invented and produced an improved form of double spiral filamentfor incandescent electric lamps; and my presentinvention is an improvedformer or shaping implement upon which the filaments are wound andsecured preliminary to the baking process to which they are necessarilysubjected.

The details of construction are as hereinafter described and claimed,and illustrated inthe accompanying drawings, in which- Figures 1 and 2are different side views of my improved former. .Fig. 3 is a perspectiveview of the top portion of the former. Fig. at is a horizontal sectionon the line 4 4 of Fig. 1. Fig. 5 is a horizontal section on the line 55 of Fig. 1. Fig. 6 is a side view of the former with a series offilaments applied and secured thereto in the manner required forthebaking operation.

The former A is composed of powdered carbon compressed to the requisitedegree and forming a hard solid cylinder. The upper portion of the bodyA of the former is provided with two adjacent spiral grooves a'and whoselower portions extend lengthwise of the former on the opposite sidesthereof, as shown in Figs. 1 and 5. At the top of the former A thegrooves a and a are connected, as shown at a-that is to say, by apassageway between two projections or ears a which are arrangeddiagonally opposite each other. The function of these ears is to holdthe carbon filaments w in place when applied therelaid with theircentral portions in the space a between the cars a and a and are woundspirally around the body of the former, so as 55 its attached filaments,is ready for the baking 6o operationthat is to say, to be placed in abed of powdered graphite and to be subjected for a period of thirty toforty hours to a high degree of heat, so as to be thoroughly baked.

In such baking process the binding-thread is burned off, and when theformer, with the filaments clinging thereto, is removed from thegraphite and duly cooled the filaments are carefully detached andseparated and are nearly in the shape required for use in lamp- 7obulbs. It will be observed that the shorter cars a are beveled on theirouter sides. This con= struction and the relative arrangement of thelonger ears a have considerable utility in function-that is to say, thelonger ears serve to hold in place any number of filaments that thegrooves a and a can accommodate, and the smaller cars a supplement thisfunction by allowing the spirally-formed filaments to be convenientlydetached after baking, since it is apparent the top bend of thefilaments will pass easily over the bevels of the ears a if the bundleof filaments be turned or rotated around the body of the former.

While I prefer and have described the former as cylindrical, I do notrestrict myself to such shape, since it may be made elliptical incross-section and still serve the purpose.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. An improved former for filaments of incandescent lamps, the samehaving two opposite spiral grooves leading downward from its upper end,substantially as shown and described.

2. An improved former for filaments of incandescent electric lamps, thesame being shaped as described, and having two similar I00 spiralgrooves in its upper portion and two opposite straight grooves in itslower portion, which grooves are joined with the spiral ones, as shownand described.

3. The improved former for the purpose specified, consisting ofacylindrical body having a passage-way at the top and two spiral groovesleading downward therefrom on opposite sides as shown and described.

4. The improved former for the purpose specified, consisting of acylindrical carbon body having a passage-way at the top and two spiralgrooves leading downward therefrom on opposite sides and terminating instraight portions parallel to the central axis of the former, as shownand described.

5. The improved former for the purpose specified, consisting of a roundbody having opposite ears at the top which are separated by a spacesuitable to receive a bundle of carbon filaments, and two similar spiralgrooves leading downward on opposite sides and ter-= minating instraight portions which are also 7

